[Mono-list] Small-medium project
Duco Fijma
duco@lorentz.xs4all.nl
Fri, 20 Jul 2001 23:20:31 +0200
(Excuse me, Miguel, for accidentially replying this to you personally
just a second ago)
Miguel de Icaza wrote:
>
> I ran into an interesting class while trying to bootstrap the
> mono-interpreter, the class is `System.DateTime'.
>
> For now I have just put a blank implementation (so I can get things
> going).
If somebody didn't picked this up before I return from my vacation in
three weeks, I might have a look at it :-)
Just a thought on the calender: when the new millenium started on
January 1th, 2001, I wondered whether it was a coincidence that this day
was a Monday (which is, except in the US :-), the first day of the
week). I discovered (I apologize if this is a known fact) that a period
of 400 years has one very nice propertu: the number of leap years in
such a period is an exact multiple of 7. 400 years is exacly 20871
weeks!
If a date were stored according to this observation (e.g, store "1984"
as "the 384th year of the 5th quadcentury"), this would highly
simplifies date calculations involving leap years and the "day of the
week". 1/1/1, the day our calendar started, was a monday, as were
1/1/401, 1/1/801, etc upto and including 1/1/2001.
Of course, as Miguel said, we have to apply corrections from the current
Gregorian calender to earlier calenders (that differ per
country/region).
Duco